Numerous medical procedures are known which involve tubular fluid conduits such as blood vessels. One such procedure, known as percutaneous transluminal angioplasty, involves the use of an angioplasty balloon catheter in a minimally invasive treatment to enlarge a stenotic or diseased blood vessel. In order to prolong the positive effects of percutaneous transluminal angioplasty, a stent may be implanted in conjunction with the procedure to provide radial support to the treated vessel. A thrombectomy is another minimally invasive procedure that may be conducted in lieu of a percutaneous transluminal angioplasty. It is a procedure that can be used to remove an entire thrombosis or a sufficient portion of the thrombosis to enlarge the stenotic or diseased blood vessel. Atherectomy is another well-known minimally invasive procedure that mechanically cuts or abrades a stenosis within the diseased portion of the vessel. Ablation therapies are further alternative therapies that use laser or RF signals to superheat or vaporize the thrombosis within the vessel.
During each of the above procedures, there is a risk that dislodged emboli will travel into smaller diameter regions of the vasculature, blocking blood vessels and causing ischemic injury. This problem is especially severe where the emboli are permitted to travel into the coronary arteries and cerebral arteries, and can result in infarction, stroke and even death. Thus, practitioners have approached prevention of escaped emboli through use of a number of techniques, including the capture of emboli in a filter or occlusion device positioned distal to the treatment area.
Emboli filtration devices are known in which filter elements are deployed against the walls of a vessel distal to a stenosis. Such filters typically comprise a polymer or wire filtration element mounted on a distal region of a guide wire or angioplasty catheter. Blood is permitted to flow through the filter while trapping emboli. Once treatment of the stenosis is completed, the filter containing the captured emboli is contracted and withdrawn from the vessel. Examples of prior art filters can be found, for example, in U.S. Patent Application Pub. No. US 2002/0022858 A1, U.S. Patent Application Pub. No. US 2002/0045916 A1, U.S. Patent Application Pub. No. US 2002/0004667 A1, and U.S. Patent Application Pub. No. US 2001/0012951 A1, the disclosures of which are hereby incorporated by reference.
In view of the foregoing needs, a novel filtration apparatus, which can be used to remove emboli from blood, for example, is clearly of interest to those skilled in the art.
A second group of procedures involving tubular body fluid conduits are procedures in which an anastomotic connection is made between the conduits. An anastomotic connection, or anastomosis, is a connection that allows body fluid to flow between the lumens of the two conduits that are connected, generally without allowing body fluid to leak from the conduits at the point of connection.
A coronary bypass procedure is one example of a procedure involving an anastomosis. Typically, in order to bypass an obstruction in a patient's coronary artery, a tubular graft supplied with aortic blood may be connected via an anastomosis to the contrary artery downstream from the obstruction. In many cases, the anastomosis is formed between the end of the graft and an aperture in the sidewall of the coronary artery (a so-called end-to-side anastomosis). The graft may be a natural conduit, an artificial conduit, or a combination of natural and artificial conduits (e.g., natural tubing coaxially disposed inside artificial tubing). If natural conduit is used, it may be wholly or partly relocated from elsewhere in the patient (e.g., a wholly relocated saphenous vein or a partly relocated internal mammary artery). More than one anastomosis may be needed. For example, a second anastomosis may be needed between an upstream portion of the graft conduit and the aorta or the coronary artery upstream from the obstruction in that artery. Again, this second anastomosis is frequently an end-to-side anastomosis. Alternatively, no second, upstream anastomosis may be required at all (e.g., if the graft is an only-partly-relocated internal mammary artery).
Currently, the most common technique for making an anastomosis is to manually suture the two tubular body fluid conduits together around an opening between them. Manual suturing is difficult and time-consuming. In the case of coronary artery bypass procedures, one source of difficulty for suturing of an anastomosis may be motion of the heart.
Sutureless anastomosis techniques are known, for example, from U.S. Pat. Nos. 6,309,416 and 6,302,905 assigned to St. Jude Medical Cardiovascular Group, the disclosures of which are hereby incorporated by reference. Both of these references describe techniques in which a connector device is used in providing an anastomosis between two tubular body fluid conduits in a patient. Deployment of such connectors is also significantly less invasive than techniques that require suturing.
In view of the foregoing, a novel apparatus that can be used to make an anastomotic connection in lieu of manual suturing is clearly desirable.